The present invention relates to a position data interpolation method, a position detecting sensor, and a position measuring device in case position measurement cannot be performed by using GPS (Global Positioning System).
In recent years, position measurement using GPS has become widespread. For example, when civil engineering work is carried out by using civil engineering equipment such as a bulldozer, a working position, i.e. a position of the bulldozer, is measured by using a GPS, and confirmation of the working position and the like are performed. Or, as in a car navigator, an electronized map information is linked with position data of a mobile object obtained by using the GPS, and a present position is reflected on an electronic map and is turned to an image, and this is displayed on an image display device. In this way, it is possible to measure a position of a mobile object at real time.
However, an electric wave from a satellite is used in the position measurement by using GPS. In case the electric wave from the satellite is interrupted by an obstacle, e.g. by a mountain, a building, etc., there is a place (shade) where the electric wave does not reach. Or, as in a case of a car navigator, when a position measuring range cannot be determined, there is a portion of the shade.
In the past, in a zone where position measurement cannot be performed by using GPS, it is necessary to add surveying operation by human power using surveying instrument as in the conventional case, and the operation must intermittently performed.
Also, on a device such as a car navigator installed on a mobile object, position measurement has not been achievable in a portion of the shade, and sufficient functions have not been fulfilled as a position measuring device.